Process of producing a milled nonsoap detergent in bar form



Patented May 18, 1954 UNITED STATES PATENT OFFICE PROCESS 0F PRODUCING AMILLED NON- SOAP DETERGENT IN BAR, FORM No Drawing. Application August4, 1948, Serial No. 42,537

6 Claims. 1

This invention relates to improvements in synthetic detergents, and moreparticularly to an improved method of treating detergent massescomprising solid, synthetic organic detergent material to produce acompacted mass or body which is cohesive and firm, and which can bereadily formed into a commercially desirable bar or cake.

The advent of synthetic, so-called non-soap Organic detergents, hasbrought about a demand for such products in the form of bars, cakes ortablets. However, attempts so far to make them in bar form usingconventional soap making equipment and processes have raised newproblems in the milling and plodding steps of their manufacture.Inasmuch as plodding is an es sential step in the making of toilet soapin commercial quantities, it is also, so far as now known, essential tothe making of synthetic detergents in bars in commercial quantities.

Prior to this invention, however, it has been very diiiicult to produceplodded bars and cakes of these synthetic detergents commerciallywithout the addition of various fillers, diluents and the like, in suchamounts that the detergent efficiency of the surface-active constituentis greatly lowered. Moreover, attempts to make synthetic bars usingordinary soap making methods and machinery have been largelyunsuccessful because of difliculties encountered in plodding thedetergent mass to produce a product which can be readily extruded,pressed and cut into bars and cakes.

The difliculties appear to be due partly to the fact that such syntheticdetergents, in general, possess a higher wetting power and are moresensitive to changes in working temperatures than ordinary soaps,requiring in most cases that a fixed temperature be maintained duringplodding. Also, the synthetic detergent particles do not cohere readily,even in the presence of a small amount of water, so that, without theuse of an added binder, it has been practically impossible to produce afirm, coalescent bar. Otherwise attempted plodding has had essentiallythe same result as plodding crystalline salts such as sodium chloride,or like substances.

Striving to overcome this lack of cohesiveness, additions of china clayand the like inert materials have been made to some advantage, but therelatively large amounts necessary lowered the efficiency of thedetergent when in cake form.

Use of a certain amount of water in the production of milled syntheticbars or cakes also has been believed necessary heretofore in order toproduce a sufiiciently pasty mass for plodding. In fact, prior to thisinvention, it has been the general practice to provide the detergentbody which was to be milled or plodded with a moisture content of fromabout 10 to 20%, and even a higher moisture content has beenrecommended. Lower percentages of moisture content than about 5% werebelieved to be undesirable, because there has been indications that asthe moisture content is lowered it becomes increasingly more difficultto mill and especially to plod such a detergent mass.

It has now been discovered, however, that the difiioulties encounteredin plodding these solid, synthetic detergent masses to produce acompacted detergent body suitable for forming into cars and cakes may besubstantially overcome, or greatly lessened, by employing low moisturecontent material which is plasticized by the addition of high-boilingorganic plasticizers of limited solubility in water which broaden theplastic range, and by carrying out the plodding operation while thedetergent mass is heated within this broadened temperature range whereinthe same remains plastic and workable.

The invention in its broadest aspect comprises the improvement in theprocess or plodding a detergent composition comprising essentiallysolid, synthetic, organic non-soap detergent material which comprisesheating and plodding the synthetic detergent mass while the same is oflow or reduced moisture content, and contains sufficient amount of ahigh molecular weight organic compound or mixture of organic compoundswhich function both as a plasticizer and a plasticity modifier so thatthe plasticity range or temperature at which the detergent mass may beplodded is considerably wider than otherwise would be the case.

Suitable amounts of other substances, such as fillers, builders,coloring material, perfume, etc. also may be incorporated to produce afinished product having the physical characteristics desired. Thetemperature to which the detergent mass is subjected during ploddingwill depend largely upon the particular synthetic material used as wellas the plasticizer employed, but is sufiicient to maintain the mass softand workable but not so high as to convert the same into a liquid state.

In accordance with this invention the moisture content of the detergentmass is reduced to a low percentage amount, or such that it does notcontain more than about 5% by weight and preferably is below 2%, Asuitable amount of a nonvolatile high molecular weight organicplasticity modifying agent is incorporated, and the mass is heated to aplastic state and plodded while thus heated. By employing such a methodit has been found that the detergent mass can be readily plodded into acohesive, homogeneous, uniform body which can be extruded in the form ofa bar, and which in turn, may be cut into blanks and pressed into firm,smooth cakes.

Several important advantages are obtained by utilizing the presentinvention of producing synthetic detergent bars and cakes. For instance,by reducing the moisture of the detergent mass rather than byincorporating water or watercontaining ingredients, and by incorporatingan organic plasticizer which widens the plasticity range and dissolvesbut slowly in water, and plodding the mass while heated, the degree ofsoftening can be controlled and a firm, non-sticky bar produced.Moreover, by lowering the moisture content of the detergent mass suchthat further drying out of the same becomes negligible, the problemsencountered due to substantial changes in the moisture content, as mayresult due to evaporation, are avoided.

It has been observed that the working temperature for plodding solidsynthetic non-soap detergent m a s s e s, containing appreciable amountsof water, generally lies within a critical range of a few degrees, and,unless strict control is exercised, sticking and damage to the equipmentand/ or synthetic product during plodding may result. In some cases,Where the mass is. allowed to vary a few degrees from this criticaltemperature during plodding, the detergent mass sets either too rapidlyor too slowly, so that the batch can not be used. Moreover, unless sucha batch is reworked immediately, it may have to be discarded inasmuch asupon aging it tends totake on a permanent hardening eliect or otherwisechange physically, so that it can not be properly disseminated andevenly distributed. through a subsequent detergent mass.

The ease by which scrap can be reworked is one of the importantadvantages of the present process. In this regard, it has been observedthat the detergent body after plodding can be stored and later reworkedwithout it having changed its composition or physical state to suchextent that the mass can not be properly reworked into a. subsequentdetergent mass. Thus, significant advantages are gained from amanufacturing standpoint through the elimination of scrap, the reductionin labor and handling cost, and the decrease in floor space requirement.

Various solid non-soap synthetic detergents may be used in making theplodded detergent body in accordance with this invention. For example,the non-soap synthetic detergent material may include the solid,water-soluble salts of one or more sulfated or sulfonated organiccompounds, the alkyl radical groups of which contain at least eightcarbon atoms, such. as higher fatty alcohol sulfates (Gardinols),sulfated or sulfonated monoglycerides i. e. sodium glyceryl monolauratesulfate (Syntex M), secondary alcohol sulfonates i. e. dioctyl sodiumsulfosuccinate (Aerosol O. '13.), alkyl aryl sulfonates i. e. sulfonatedbenzene which contains an alkyl substituent of about to 14 carbon atoms(Oronite, Santomerse, Ultrawet, Kreelons, Nytron, etc), alkyl sulfonatesi. e. sodium alkyl sulfonates produced from petroleum or similarhydrocarbons (Mersolates, Merpols, etc.), fatty acid esters of alkylhydroxy or amine sulfonic acid i. e. sodium B-oleylethanesulfonate(Igepon A) and sodium ,8 amine ethanesulfonate (Igepcn T), and otherwater-soluble salts of other sulfuric reaction products of highmolecular weight organic compounds which are characterized by their highsolubility in water and superior detergent properties. Nonionic, solidsynthetic detergents may be used, i. e. polymerized ethylene oxidecondensates, fatty acid polyoxyethylene derivatives, etc., and marketedunder such names as Biopal, Sorapal, Igepal, etc. Also mixtures of thenonionic type detergents with ionic detergents may be utilized.

Substances employed as plasticizing agents are organic compounds whichare solids, semi-solids or oily liquids at ordinary temperatures and ofthe high boiling non-volatile type havin limited solubility in water, orat least dissolve very slowly therein. They are also resistant tocrystallization and segregation under the diiferent temperature andaging conditions to which the detergent bar or cake may be subjec' edduring storage and use. The plasticizing substances which are solid orsemisolid, and which maintain a more or less definite form at ordinarytemperatures, are hereinafter referred to as normally solid substances.

Organic compounds which have been found to function satisfactorily asplasticizing agents which broaden the plasticity range, asaforementioned, are the high molecular weight fatty acid esters ofpolyhydrlc alcohols. For example, long-chain polyhydric alcohol mono anddistearates and particularly the ether-alcohol fatty acid esters, i. e.diethylene glycol mono and distearates, being especially useful. lhesecompounds also function as emulsifying agents, thus promoting theformation of a synthetic detergent bar having a smooth, uniform texturethroughout. Other organic plasticizing agents which may be used are thenormally solid polyethylene glycols (a known product being sold underthe name Carbowax), glycerol mono esters of coconut fatty acids,ethylene glycol distearate, and the diethylene glycol mono and di-estersof palmitic, myristic, oleic, lauric and coconut oil acids; propyleneglycol mono and di-esters of stearic, oleic, lauric, myristic, palmitic,coconut oil fatty acids, etc., as well as suitable glyceryl and ethyleneglycol mono esters of such fatty acids, and the like, which esters arenormally solid, or Olly liquids, and which dissolve in water but at aslow rate. Mixtures of the various organic compounds may, of course, beemployed. Where, however, substances are used which are readilydissolved in water there is a tendency towards the production of a barwhich is not as firm and dry to the touch as otherwise, and the finishedbar or cake dissolves less slowly in water. A plodded detergent bar,which contains plasticity modifying agent as herein described, hardensgradually upon standing in the air at room temperatures without changingits other physical properties or its chemical properties.

. The required proportion of plasticizer varies depending upon thecomposition to be plodded and the plasticizing agent employed. Additionsof relatively small amounts up to 20% or more by weight of the detergentmass may be utilized to advantage.

The moisture content of the synthetic detergent mixture plcdded ispreferably reduced as much as practicable, as by initially spray dryingor roll drying the mass prior to plodding so that most or practicallyall the water is removed.

This facilitates the plodding operation. When, however, the moisturecontent of the mass is substantially above 5% by weight it is difficultto plod satisfactorily, the mass tending to become very soft approachinga liquid state. Moreover, as the water content is further increased, theextruded bar and cakes made therefrom become increasingly softer,presenting relatively sticky surfaces which is undesirable. Aside fromthese disadvantages, finished bars or cakes made from the highermoisture content material. dissolve inv water at a much faster rate thandesired, and they do not dry to a hard firm cake after each use.

The lower water content of the synthetic detergent mass from which thebars and cakes are produced in accordance with this invention, has thefurther advantage of permitting the exercise of some control over thespeed at which the synthetic cake dissolves in water. For example, byvarying the proportion of the constituents while maintaining thesynthetic detergent mass substantially anhydrous, the water dissolvingproperties of the finished bar or cake may be varied, and bars madewhich dissolve in water at a slower and more satisfactory rate.

By thus providing a synthetic detergent mass which is of relatively lowmoisture content, and which contains a plasticizing agent whereby themass tends to remain plastic and workable over a fairly wide temperaturerange, for example 110 to 170 F., the plodding operation can be moreeasily and effectively carried out.

Where relatively high temperatures are employed in plodding operations,for example in the neighborhood of 200 F. or above, as may be requiredwithout a plasticizing agent, there is always the danger of producingdiscolorations in the finished bar or cake, or even destruction of thedetergent itself, due to this high temperature treatment. This, ofcourse, is undesirable and has been overcome in the novel process ofthis invention by substantially lowering the moisture content of thesynthetic detergent mass, and incorporating organic plasticizers wherebythe detergent mass can be plodded while heated to a lower temperaturethan otherwise may be required.

Utilizing a plasticized mass, as described hav ing a low moisturecontent, the plodding may be accomplished while the mass is heated toaround 115 F., or lower, although for most purposes the plodding iscarried out between about 120 and 150 F. By plodding the detergent massat this relatively low temperature and low moisture content, it is notnecessary to add preservatives as has been generally necessitated withcertain higher moisture detergent masses when attempting to plod thesame.

Any waste or scrap detergent formed may be reworked even after agingseveral days or a month without producing an inferior detergent bar.Likewise, where the plodder is stopped during operation, it isunnecessary to remove the synthetic detergent material, or disassembleand clean the plodder prior to resuming plodding, as has been oftenrequired heretofore, particularly where attempts have been made to ploda synthetic detergent body which contained substantial amounts of water.

The following specific examples are given merely to illustrate how theinvention may be practiced, the percentage amounts referred tothroughout the description being by weight.

Example I Percent by weight Sodium salt of the sulfated monoglyceridesof coconut oil fatty acids (salt-free) 78.0 Zinc stearate l 15.0Diethylene glycol monostearate 6.0 Titanium dioxide 0.5 Perfume 0.5

The synthetic detergent and the remaining in gredients, except theperfume, were suitably admixed and the mass passed through a three-rollmill several times, the perfume being incorporated near the end of themilling operation to prevent its loss by evaporation. The warm ribbonefrom the mill, which contained approximately one-half percent by weightmoisture, were then transferred to a plodder and plodded while heated toa temperature between 130 and ll0 F. The barrel of the plodder waspreheated Example If Percent by weight Sodium salt of the sulfatedmonoglycerides of coconut oil fatty acids salt-free) 67.5

Aluminum palmitate 15.0 Diethylene glycol distearate 15.0 Titaniumdioxide 1.0 Perfume 1.5

The above mixture, comprising the synthetic detergent, filler, andplasticizer was roll dried to provide a low moisture mass, and thedetergent mixture was then passed, through a three-r011 mill severaltimes during the latter part of which operation the perfume wasincorporated. Thereafter the warm ribbons formed on the roll, andcontaining approximately one percent moisture, were transferred to aplodder and plodded at a temperature of between to F. In this instance,the plodding was carried out under a vacuum, such as described in theUnited States patent to Schwa-ntes 2,146,770, to produce a higherspecific gravity non-floating bar. After plodding, the mass was extrudedin the form of a bar which was cut into cakes or blanks and pressed in adie to provide a finished cake of the desired shape and markings. Theextrusion nozzle of the plodder was heated somewhat above the ploddingtemperature, as in Example I, to produce an extruded bar having asmooth, even surface.

Example III and di-stearates of diethylene glycol) 8.0 Titanium dioxide0.5 Perfume 0.5

The spray dried solid synthetic detergent and remaining ingredients weresuitably admixed and aeaaoer milled as described in Example I. The warmribbons from the mill, and which contained approximately one andone-half percent moisture, were then transferred to a preheated plodderand vacuum plodded as described in Example II. A smooth plodded bar wasobtained which was cut into blanks to form cakes.

Example IV Percent by weight Sodium salt of the sulfated monoglyceridesof coconut oil fatty acids (salt-free) 48.0 Igepon T (sodiumfl-oleyl-amino-ethanesulfonate) 2.0 Boric acid 23.0 Disodium diacidpyrophosphate 10.0

Carbowax 4000 (solid polyethylene glycols) 10.0

Glycerine 1.0 Sodium soap chips 2.0 Irish moss 2.0 Titanium dioxide 1.0Perfume 1.0

The above mixture of constituents, except the perfume, were suitablymixed and roll dried with lbs. of steam to produce a low moisture mass.

Example V Percent by weight Sodium salt of the sulfated monoglyceridesof coconut oil fatty acids (35% active synthetic) 88.75 Diethyleneglycol monostearate 10.00 Coloring material 0.25 Perfume 1.00

The constituents were admixed similarly as in Example I to provide a lowmoisture mass which was plodded while heated to between 115 and 125 F.

Example VI Percent by weight Oronite (sodium salt of alkyl arylsulfonate active synthetic) 87.00

Diethylene glycol monostearate 4.00 Zinc stearate 7.00 Titanium dioxide1.00 Perfume 1.00

The above ingredients were roll dried as in Example IV to produce a lowmoisture mass which was plodded while heated to between 120 and 130 F.

Example VII Percent by weight Spray-dried Igepon AP (sodium salt of 13-laurylethanesulfonate active synthetic) 80.00 Magnesium stearate 12.00Diethylene glycol monostearate 6.00 Titanium dioxide 1.00 Perfume 1.00

The constituents were suitably mixed as described in Example I toprovide a detergent mass having a low moisture content. The mass wasthen plodded while heated to between and Example VIII Percent by weightSpray-dried sodium salt of the sulfated monoglycerides of a mixturecontaining 65% hydrogenated tallow and 35% hydrogenated coconut oil 10%active synthetic) 82.0 Zinc stearate 12.0 Diethylene glycol monostearate5.0 Titanium dioxide 0.5 Perfume 0.5

The ingredients were admixed as described in Example III to provide alow moisture detergent mass which was heated to a temperature between130 and F. and plodded.

Example VIII illustrates the use of sulfated hydrogenated tallow andcoconut oil in place of coconut oil fatty acids, or the like fatty oilacids. Mixtures of hydrogenated tallow with fatty oil acids i. e.stearic, palmitic, etc., may also be utilized. Further, by varying thepercentage amounts of hydrogenated tallow used, a bar having higher orlower solubility may be produced. In general, with the use of higheramounts of hydrogenated tallow there is produced correspondingly lowersolubility bars, but with increased amounts the sudsing and latheringproperties of the bars are lessened which for some purposes areundesirable.

Instead of employing the relatively pure salt of the sulfated orsulfonated monoglycerides of coconut oil fatty acids, the syntheticdetergent may contain relatively large or small amounts of sodiumsulfate or such other salts as may be formed during neutralization ofthe sulfated or sulfonated substances. Furthermore, the addition agents,i. e. fillers, builders, coloring matter, etc., may be omittedaltogether, if desired, or added in substantially reduced amounts suchas illustrated in Examples V and VI.

The proportionate amounts of the components used in making the ploddeddetergent mass are not critical and may be widely varied andsubstitutions made depending upon the properties wanted in the finalproduct. Likewise the synthetic detergent may comprise relatively largeor small amounts of salts or modifying agents, such as may be formedduring production of the synthetic detergent salt, as aforementioned, oras subsequently incorporated.

The addition of inorganic builders, such as phosphates, carbonates,bcrax, etc., and/or organic builders, i. e. carboxymethylcellulose,higher fatty acid alkylolamides, and etc., may be made to obtain certaindesired detersive characteristics. Inorganic or organic coloringmaterials, 1. e. pigments, dyes etc., may be utilized to give theplodded detergent mass or bar a pleasing color or tint. Some coloringmaterials, such as titanium dioxide, function both as a color embodyingagent and a hardener.

Glycerine may be incorporated, as is illustrated in Example IV, toimpart emollient characteristics to the finished bars or cakes, and toenhance their gloss. Olive oil also may be used for this purpose, and ifdesired germicidal substances may be added which are compatible andstable.

Although the sodium salts of the different sulfated or sulphonatedsynthetic detergents are generally preferred, other salts may be used,and may be more advantageously employed in certain instances. Forexample, the corresponding salts of calcium, barium or magnesium, ormixtures thereof may be utilized.

Various methods may be employed to heat the plodder, such as by the useof fluid heated jackets, electrical resistances or the like, the plodderbeing heated sufliciently to cause the detergent mass to become plasticand workable, but not so high as would transform the mass into a liquidstate or melt. The nozzle of the plodder is heated so that itstemperature is somewhat above that of plodding in order to produce anironing effect on the detergent mass as it is extruded, smoothing outany slight imperfections at the surface which might otherwise produceperceptable serrations on the surface of the bar as it is extruded.

What is desired to be protected by Letters Patent is:

1. In the process of producing a milled nonsoap detergent in bar formconsisting essentially of detergent material and a plasticizer, saiddetergent material being a water-soluble salt of an organic sulfuricreaction product having in its molecular structure a radical selectedfrom the group consisting of sulfonic and sulfuric acid ester radicalsand said plasticizer being a normally solid ether-alcohol fatty acidester which dissolves slowly in water, the steps which comprise dryingthe detergent material to a moisture content of not more than by weight,incorporting up to 20% by weight of said plasticizer, heating theresulting mass to a temperature between 110 and 170 F. to render thesame plastic and workable but insufficient to cause liquefication of thesame, and subjecting said mass while thus heated to a plodding treatmentto form a compacted, firm, cohesive detergent body.

2. In the process of producing a milled nonsoap detergent in bar formconsisting essentially of detergent material and a plasticizer, saiddetergent material being a water-soluble salt of an organic sulfuricreaction product having in its molecular structure a radical selectedfrom the group consisting of sulfonic and sulfuric acid ester radicalsand said plasticizer being a normally solid partial ester of along-chain fatty acid and a polyhydric alcohol, the steps which compriseremoving moisture from the detergent material to reduce the moisturecontent so that it is not more than 5% by weight, incorporating up to20% by weight of said plasticizer, heating the resulting plasticizedmass to a temperature between and F. to render it plastic and workable,and subjecting said mass while thus heated to a plodding treatment toproduce a compacted cohesive detergent body.

3. In the process of producing a milled nonsoap detergent in bar formconsisting essentially of detergent material and a plasticizer, saiddetergent material being a water-soluble salt of an organic sulfuricreaction product having in its molecular structure a radical selectedfrom the group consisting of sulfonic and sulfuric acid ester radicalsand said plasticizer being normally solid diethylene glycolmonostearate, the steps which comprises drying said detergent materialsto produce a detergent mass having a moisture content of not more than5% by weight, incorporting up to 20% by weight of said plasticizer,heating the resulting plasticized mass to a temperature between 110 and170 F. to render the same plastic and workable, and plodding said masswhile thus heated to produce a compacted cohesive detergent body.

4. A process as set forth in claim 1 in which said detergent materialcomprises a water-soluble salt of the sulfuric acid ester of a highmolecular weight fatty acid monoglyceride.

5. A process as set forth in claim 1 in which said detergent materialcomprises a water-soluble salt of alkyl aryl sulfonates.

6. A process as set forth in claim 1 in which said detergent materialcomprises a water-soluble salt of an alcohol sulfonate.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,356,903 Wood Aug. 29, 1944 2,462,758 Malkemus Feb. 22, 1949FOREIGN PATENTS Number Country Date 477,521 Great Britain Dec. 28, 1937

1. IN THE PROCESS OF PRODUCING A MILLED NONSOAP DETERGENT IN BAR FORMCONSISTING ESSENTIALLY OF DETERGENT MATERIAL AND A PLASTICIZER, SAIDDETERGENT MATERIAL BEING A WATER-SOLUBLE SALT OF AN ORGANIC SULFURICREACTION PRODUCT HAVING IN ITS MOLECULAR STRUCTURE A RADICAL SELECTEDFROM THE GROUP CONSISTING OF SULFONIC AND SULFURIC ACID ESTER RADICALSAND SAID PLASTICIZER BEING A NORMALLY SOLID ETHER-ALCOHOL FATTY ACIDESTER WHICH DISSOLVES SLOWLY IN WATER, THE STEPS WHICH COMPRISE DRYINGTHE DETERGENT MATERIAL TO A MOISTURE CONTENT OF NOT MORE THAN 5% BYWEIGHT, INCORPORTING UP TO 20% BY WEIGHT OF SAID PLASTICIZER, HEATINGTHE RESULTING MASS TO A TEMPERATURE BETWEEN 110* AND 170* F. TO RENDERTHE SAME PLASTIC AND WORKABLE BUT INSUFFICIENT TO CAUSE LIQUEFICATION OFTHE SAME, AND SUBJECTING SAID MASS WHILE THUS HEATED TO A PLODDINGTREATMENT TO FORM A COMPACTED, FIRM, COHESIVE DETERGENT BODY.